Komatsu PC210LC-10 Fault Code CA1695: Technical Guide

What is Komatsu PC210LC-10 Fault Code CA1695?

Fault Code CA1695 indicates a malfunction in the Engine Control Module (ECM) communication circuit with the Machine Controller (MC), specifically detecting an abnormal CAN bus signal or communication failure between these critical control systems.

This diagnostic trouble code (DTC) is part of Komatsu's KOMTRAX integrated monitoring system on the Dash-10 series excavators. The PC210LC-10 relies on continuous CAN (Controller Area Network) communication between the engine ECM and the machine controller to coordinate engine performance, hydraulic functions, and operational monitoring. When this communication link fails or degrades, the machine cannot properly optimize fuel delivery, emission controls, or hydraulic system coordination, potentially resulting in reduced performance and unsafe operating conditions.

This code is particularly critical because both controllers share essential data including engine load demands, regeneration requests for the diesel particulate filter (DPF), and hydraulic pressure requirements.

Common Symptoms

• Machine Controller warning light illuminated on the monitor panel with reduced engine power output
• Engine derate mode activated, limiting maximum RPM to approximately 1,500-1,800 range
• Intermittent loss of hydraulic responsiveness or sluggish multi-function operation
• KOMTRAX dashboard displaying communication error messages or blank engine parameter readings
• Difficulty initiating DPF regeneration cycles or emission system faults appearing simultaneously

Potential Causes

The most common technical failures triggering CA1695 on used PC210LC-10 excavators include:

• CAN bus wiring harness damage at known rub points near the engine mounting bracket and along the right-side chassis rail where cables route past hydraulic lines
• Corroded or moisture-contaminated connectors at the ECM (located behind the operator cab) or MC junction points
• Faulty termination resistors on the CAN network (120-ohm resistors that should measure approximately 60 ohms across the bus)
• ECM or Machine Controller internal failure, though less common than harness issues in higher-hour used machines
• Voltage supply problems from the main power distribution causing intermittent controller resets

How to Troubleshoot and Fix Code CA1695

Step 1: Visual Inspection and Connector Verification

Begin by inspecting all CAN bus harness routing from the engine ECM to the machine controller. On used excavators, focus on areas where the harness contacts frame members or passes near heat sources. Check connector C-101 (ECM main connector) and C-215 (MC interface connector) for corrosion, bent pins, or moisture intrusion. Clean contacts with electrical contact cleaner and apply dielectric grease.

Step 2: CAN Bus Resistance Testing

Using a digital multimeter with the key switch OFF and both connectors disconnected, measure resistance between CAN-H and CAN-L terminals. You should read approximately 60 ohms (two 120-ohm termination resistors in parallel). A reading of 120 ohms indicates one missing terminator; infinite resistance means an open circuit in the harness.

Step 3: Monitor Live Communication with Diagnostic Software

Connect Komatsu KDPF diagnostic software (or compatible CAN analyzer tool) to verify real-time communication packet transmission. Monitor for message error rates exceeding 5% or complete signal dropouts. Check battery voltage at the ECM during cranking—voltage drops below 10.5V can cause temporary communication failures on used machines with aging batteries.

Step 4: Harness Continuity and Isolation Testing

With connectors still disconnected, verify continuity on CAN-H and CAN-L wires individually from ECM to MC. Check for short circuits to ground (should read infinite resistance). Pay special attention to harness sections routed along the right-side swing bearing area where cable abrasion commonly occurs on machines with 5,000+ operating hours.

Step 5: Component Replacement Protocol

If harness and connections test properly, perform a controller swap test if possible. Replace the machine controller first as it has higher failure rates than the engine ECM. After any component replacement, perform a CAN bus initialization procedure using diagnostic software and clear all codes before testing.

For used excavators, always address underlying causes like improved harness routing with additional protective loom or upgraded connector sealing to prevent recurrence.

---

Disclaimer: This guide provides general diagnostic procedures for experienced diesel mechanics. Always consult the official Komatsu PC210LC-10 Shop Manual and use proper safety procedures. If unfamiliar with high-voltage systems or CAN diagnostics, seek assistance from a certified Komatsu technician.